#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main() {
    int sum = 0;
    int time = 2;
    scanf("%d", &sum);
    int i = 0;
    while (sum >= 12) {
        sum -= 12;
        time += 4;
    }
    printf("%d", time);
    return 0;
}